The present invention relates to connectors, and, in particular, to an improved breathing circuit connector for intercoupling between the flexible hoses of an anesthesiology machine and the input of an endotracheal tube connector.
The conventional breathing circuit connector consists of a hollow cylindrical body of rigid or semi-rigid plastic material having a straight or tapered male input section, a normally straight female output section, and a cylindrical bore extending between the input and output sections or ends. The connector may be shaped as an elbow with the longitudinal axis of the bore portion within the input section being displaced 90.degree. from the longitudinal axis of the bore portion within the output section. Alternatively, the bore may extend in a straight line or it may be curved. Another type of breathing circuit connector consists of a single female output section and a pair of male cylindrical sections displaced from each other, the connector being in the shape of a Y. The output female section of the conventional cylindrical breathing circuit connector has a bore of standard, uniform diameter, i.e. fifteen millimeters, and is adapted for coupling to the male input section of an endotracheal tube connector. The male input section of the breathing circuit connector is adapted for insertion either into the flexible, corrugated hose from an anesthesiology machine or for insertion into the output female section of the conventional Y-shaped connector. The two male sections of the conventional Y-shaped connector are securely attached, respectively, to two separate and independent flexible hoses from the anesthesiology machine, as by cementing.
Prior art breathing circuit connectors have been found to possess a rather serious problem in attempting to maintain a secure, air tight coupling between a tapered male input section and a corresponding female output section. When the material forming the male input section is composed of a relatively rigid or semi-rigid plastic or polymer material, such as nylon, polyethylene or polypropylene, a rather strong force is needed to insure that the male input section is firmly inserted into the female output section. Where the female output section has either a straight, uniform, cylindrical internal diameter, or a tapered internal diameter, the coupling between the male and female sections has been found to work loose and, at times, to become completely disconnected. This has been especially true when the material forming the female output section is also composed of a relatively hard or semi-rigid material. The failure of the breathing circuit connection, either during an operation or in post-operative recovery, represents a very serious hazard to the health of the patient. The same danger exists where the female output section of the conventional elbow, or 90.degree. breathing circuit connector, is coupled to a tapered male input section of the conventional, hard plastic, endotracheal tube connector. The problems also exist between the coupling between the female output section of the conventional Y-shaped breathing circuit connector and the male input section of the conventional endotracheal tube connector.
One solution to the above problem has been to employ bands, cords or adhesive to bind together each connection in the breathing circuit coupling. To facilitate the use of cords or bands, a crown frequently is formed atop the hard plastic breathing circuit connector to serve as a base or anchor to which the bands, cords or adhesive may be attached.
Another solution has been to employ breathing circuit connectors formed of resilient material having a somewhat higher coefficient of friction in the hope that the required air-tight coupling will be retained. With this type of connector, it is very difficult to disconnect the coupling, as is often required during an operation.
Still another solution has been to employ breathing circuit connectors designed to include an external ridge or ring upon the outside surface of the male input section i norder to engage a mating internal groove formed inside the female section of the connector, as disclosed in the U.S. Pat. Nos. 3,552,778 and 4,152,017.
A partial solution to the above problem has been the introduction of an improved endotracheal tube connector having a male input section consisting of a series of three external stepped diameter portions, as described in my U.S. Pat. No. 4,369,911. This particular endotracheal tube connector has been found to maintain a secure and reliable air-tight coupling to the female output section of the standard fifteen millimeter breathing circuit connector.
The present invention overcomes the above problems by the elimination of the tapered, or the straight bore, of the female output section of the conventional breathing circuit connector. This is achieved by designing the internal bore in the form of a series of straight and uniform internal diameter bore portions of slightly different diameters. This design feature enables one or more of the internal bore portions to seat upon the male input section of the endotracheal tube connector or upon the male input section of the conventional elbow breathing circuit connector in such manner as to reduce the internal forces that normally cause the coupling to separate and, thereby, disconnect.
A principal object of the present invention is to provide a breathing circuit connector having a more secure and reliable air-tight coupling to an endotracheal tube connector.
Another object is to provide a breathing circuit connector which is easier to connect to and to disconnect from an endotracheal tube connector.
A further object is to provide a breathing circuit connector suitable for use with endotracheal tube connectors of different manufacture.
Still another object is to provide a breathing circuit connector capable of achieving an airtight coupling despite small dimensional variations in the material forming the connector.
The above objects of and the brief introduction to the present invention will be more fully understood, and further objects and advantages will become apparent, from a study of the following detailed description in connection with the drawings.